Apparatus for welding strip material



May 27,1969' l. R. TAYLOR 1, 3,446,933

, APPARATUS FOR WELDING STRIP MATIERIZ'AL Original Filed May a, 1962 IShe et of 12 mmvroas IRVING RTAYLOR ARTHUR L.Wn uAMs May 27, 1969 I. R.TAYLOR ETA!- APPARATUS FOR WELDING STRIP MATERIAL Sheet Original FiledMay 8, 1962 a R m w w uu mnmwm I W dT R W GR WWW m2 MW B May 27, 1969 R.TAYLOR ET AL 3,446,933 APPARATUS FOR WELDING STRIP MATERIAL OriginalFiled May 8, 1962 INVENTORS IRVING R.TAT LOR m1 ARTHUR LwaLuAms I. R.TAYLOR ET AL APPARATUS FOR WELDING STRIP MATERIAL May 27, 1969 SheetOriginal Filed May 8, 1962 5 M V/ WWW W W W Mm ,m WWW M y 1969 R. TAYLORET AL "3,446,933

APPARATUS FOR WELDING STRIP MATERIAL I 4 A Original Filed May a, 1962Shet 5 of 12 P 'Z 7? if y? INVEN7'0R5 IRVING R- T my! ARTHUR L.W|1 L|AMsMay 27, 1969 l. R. TAYLOR ET AL 3,446,933

APPARATUS FOR WELDING STRIP MATER I AL Original Filed May a, 1962 Sheet6 0:12

mmv'rons IRVING R. TAYLOR.

ARTHUR L-WILUAMS y 7, 1969 I. R. TAYLOR ETAL 3,446,933

APPARATUS FOR WELDING STRIP MATERIAL Original Filed May a, 1962 Sheet 70:12

INVENTORS IRVING R. TAYLOR.

w ARTHUR L-WILLlAMS A T TOR/V15 7s May 27, 1969 Y OR ETAL 3,446,933

APPARATUS FOR WELDING STRIP MATERIAL Original Filed May a. 1962 Sheet of12 ARTHUR LxWlLLlAMS A fro/WW7;

May 27, 1969 1 l. R. TAYLOR ET AL 3,446,933

APPARATUS FOR WELDING STRIP MATERIAL Original Filed May a, 1962 Sheet 9or 12 INVENTORS IRVING R-TAYLOR w ARTHUR L-WILLIAMS :1 Ego g BT%/%M 9 5A TTORNA-XS R. TAYLOR ET AL 3,446,933 APPARATUS FOR WELDING STRIPMATERIAL Original Filed May 8, 1962 May 27, 1969 INVENTORS IRViNG R.TAYLOR MARTHUR L- W! LUAMS A Tram/[p Sheet /0 of12 May 27, 1969 R.TAYLOR ET AL 3,446,933 APPARATUS FOR WELDING STRIP MATERIAL I OriginalFiled May a, 1962 Sheet of 1;:

giYZ lRvl R TATLOQ MAR 0R l-WILUAMS May 27, 1969 TAYLOR ET AL 3,446,933

APPARATUS FOR WELDING STRIP MATERIAL Original Filed May a, 1962 Sheet 0112 iy /////;s

ARTHUR L-WlLuAMa United States Patent Int. Cl. B23k 11/06 US. Cl. 219-8213 Claims ABSTRACT OF THE DISCLOSURE Method and apparatus for resistanceseam welding of overlapped strip ends which have been severed, clampedand aligned for the passage of roller electrodes thereover. Means areprovided for sensing misalignment with means responsive to the sensingmeans to correctly align the strip ends. Strip marking means are alsoprovided for identification purposes.

The present invention relates to the joining of sections of stripmaterial in end-to-end relation to form a continuous strip length andthe principal object of the invention is to provide new and improvedmethods and apparatus of such character. This application is a divisionof Patent No. 3,256,419, issued June 14, 1966.

Many strip processing lines require the incoming strip to be acontinuous, unbroken length. This is necessitated because of thedifiiculty and time involved in threading the strip through the line.Moreover, in certain types of lines, the desired processing can onlytake place when the strip is running therethrough at a predeterminedspeed. Accordingly, the leading strip end which must be slowly threadedthrough the line at less than normal line speed cannot be properlyprocessed. For the above reasons, threading of strip through theprocessing line is avoided wherever possible.

Unfortunately, strip cannot be procured in indefinite lengths but isonly available in coils whose size is limited by manufacturing, handlingand shipping considerations. It is therefore common practice to feed acoil of material into a processing line and, before it is entirelyconsumed, to secure the leading end of another coil of material to thetrailing end of the first-named material coil. In this manner, acontinuous strip of material is, in effect, fed to the processing line.

Because the leading and trailing strip ends must be secured together inas short a time as possible, welding is frequently employed for suchpurpose. Welding such ends together has the additional advantage ofproviding the high-strength juncture necessary where the strip issubjected to heavy tension.

Unfortunately, it is difiicult to obtain consistently good welds betweenthe leading and trailing strip ends unless such ends are overlapped aconsiderable amount. This, however, causes the thickness of the strip tobe substantially doubled at the joint and, in many processing lines,this is highly undesirable. Attempts have been made to seam-weld theleading and trailing strip ends together with a very slight amount ofoverlap; however, prior art apparatus and methods were frequently tooslow in operation, were unreliable and/or could not produce consistentlysatisfactory results.

The hereinafter to be disclosed method and apparatus consistentlyproduces superior welds between leading and trailing strip ends by anarrow-overlap, seam-welding process which forms a joint which islittle, if any, thicker than a single strip thickness and at the speedsrequired by modern, high-speed processing lines. Other advantages willreadily become apparent from a study of the following description andthe annexed drawings.

In the drawings accompanying this specification and forming a part ofthis application, there is shown, for purpose of illustration, anembodiment which the invention may assume, and in these drawings:

FIGURE 1 is a generally diagrammatic, side elevational view of the entryportion of a strip processing line with which the present invention isassociated,

FIGURE 2 is a top plan view of the structure seen in FIGURE 1,

FIGURES 3 and 4 are views similar to FIGURE 1 but illustrating theposition of parts at different operational stages,

FIGURE 5 is an enlarged, front elevational view of a strip joiningdevice which embodies the present invention,

FIGURE 6 is a side elevational view generally corresponding to the line6-6 of FIGURE 5 but with parts on the near side removed to show theunderlying structure,

FIGURE 7 is a further enlarged sectional view generally corresponding tothe line 7-7 of FIGURE 6,

FIGURES 8 and 9 are fragmentary views similar to FIGURE 7, but showingcertain parts at different operational stages,

FIGURE 10 is a fragmentary sectional view generally corresponding to theline 10-10 of FIGURE 7,

FIGURE 11 is a fragmentary sectional view generally corresponding to theline 11-11 of FIGURE 7 but with certain portions on the near side brokenaway to better illustrate the underlying structure,

FIGURES 12 through 17 are enlarged fragmentary views at variousoperational stages, of certain parts seen in FIGURE 7,

FIGURE 18 is an enlarged, fragmentary sectional view generallycorresponding to the line 18-18 of FIGURE 1,

FIGURE 19 is an enlarged, fragmentary sectional view taken transverselythrough the shear blades of the present invention during a stage of theshearing operation, and

FIGURE 20 is a further enlarged fragmentary view of the strip ends andthe welding electrodes in transverse section in the relative positionsthey assume during the welding operation but showing them in separatedrelation for clarity.

With reference to FIGURES 1 and 2, there is illustrated strip joiningapparatus 10 at the entry end of a strip processing line 11. Pay-offreels 12 and 12a of any conventional design rotatably support coiledstrip material S, Sa respectively, which are adapted to be fed to thestrip processing line 11 through the strip joining apparatus 10. As willhereinafter appear, a set of entry pinch rolls 13, a set of exit pinchrolls 14 and entry tables 15 and 15a are associated with the device 10.

Before proceeding with a detailed description of the joining device 10and its associated parts, it may be helpful to briefly describe theoperation. Still referring to FIGURE 1, it will be noted that strip Spasses from the pay-off reel 12, over an idler roller 16, and under theuppermost roll of the entry roll set 13, through the joining device 10along a predetermined pass line, between the exit roll set 14 and to theprocessing line 11. Payoff reel 12a, having previously been loaded witha coil of strip Sa, merely stands by with the leading end of the stripSa resting upon the entry table 15 and projecting between the lowermostand center roll of the roll set 13.

Strip S will be fed longitudinally from right to left from the reel 12into the processing line 11 until the coil 8 of material S on this reelis consumed. At such time, longitudinal movement of the strip S will bestopped, it will be gripped and transversely severed by the joiningdevice 10, the leading end of strip Sa will be fed into the joiningdevice where it will be transversely severed, the trailing end of stripS and the leading end of strip Sa will then be welded together, to forma continuous strip, and strip Sa then fed longitudinally from thepay-off reel 12a to the processing line until the coil of material Sa isconsumed. While the strip Sa is being fed to the processing line, a newcoil of material S will be loaded on the reel 12 for joinder to thetrailing end of strip Sa when the latter is consumed. Thus, coiled stripwill be fed alternately from the reels 12, 12a, the trailing end of onecoil being welded to the leading end of the other to form anuninterrupted length of strip. The more specific manner and thestructure for carrying out the foregoing operations will next bedisclosed.

Turning now to FIGURE 6, joining device 10 comprises an elongated base17 which extends transversely of the path of strip travel and isvertically. enlarged at one end adjacent the path of strip travel toprovide a box-like structure having a front wall 18, a rear wall 19, atop wall 20, and side walls 21, 22 (see also FIGURES and 7) at its stripentry and exit sides respectively. For rea sons which will later becomeapparent, the front, rear and side walls have enlarged openings to whichreference will later be made.

As best seen in FIGURE 7, base 17 is generally troughlike in transversesection and has ways 23 for supporting a carriage 24 for movement in adirection edgewise of the strip. As herein illustrated, carriage 24 isprovided with rollers 25 which ride along the base ways 23 to guidecarriage movement.

Carriage 24, see FIGURE 6, is bifurcated to provide an upper arm 26spaced above the path of strip travel and a lower arm 27 spaced belowthe path of strip travel. The carriage is thus of C shape with its openend adjacent the front wall 18 of the base and its closed end adjacentthe rear wall 19 of the base in the carriage position shown in fulllines. From the foregoing, it will be evident that carriage 24 providesan open throat 28 through which the strip S travels to the processingline. Means are provided for shifting carriage 24 from its full-lineposition to its phantom-line position and in the present embodiment, anexternally threaded shaft 29 is rotatably carried by the base and isengaged with an internally threaded bracket 30 carried by the carriage.When shaft 29 is rotated in one direction, as by a motor unit 31,carriage 24 will be shifted along the base ways 23 to the right.Conversely, upon shaft rotation in the opposite direction, the carriagewill be shifted to the left.

Welding means are carried by the free ends of carriage arms 26, 27 andin the present embodiment, an upper weld wheel 32 is rotatably carriedby the upper carriage arm 26 while a lower weld wheel 33 is in opposedrelation with wheel 32 and is rotatably carried by the lower carriagearm 27. Upper weld wheel 32 is normally held against vertical movement;however, its vertical position may be adjusted by means of a hand wheelmechanism 34 to compensate for varying weld wheel diameter caused bywheel wear. On the other hand, lower weld wheel 33 is vertically moved,by means of a fluid cylinder 35, toward wheel 32 to grip the striptherebetween. It will be understood that when lower weld wheel 33 iselevated by cylinder 35 and the carriage is shifted to the right, theweld wheels will traverse the strip from edge-to-edge thereof. Suchaction will later be more fully disclosed during the latter to appear inthe description of the welding operation.

Still referring to FIGURE 6, a welding transformer 36 of any suitabledesign is carried by the rear, or right-hand end of carriage 24 and hasbus bars 37 (see FIGURE 5) extending toward the free ends of thecarriage arms 26, 27 for carrying welding current to the weld wheels.Each bus bar may be flexibly connected to a respective weld wheelsupporting structure by means of the usual laminated lead 38.

As previously mentioned, the present joining means is adapted totransversely sever the leading and trailing strip ends before weldingthem together; accordingly, shear means are provided for this purpose.As will later appear, such shear means comprises a moveable shear bladecooperable with a fixed shear blade to sever strip disposedtherebetween. Since only one of the shear blades is move able,considerable mechanism with attendant weight, costs and space is saved.

Turning now to FIGURES 7 and 11, it is an important feature of thepresent invention that the shear means is disposed within the throat 28of the carriage 24 to provide an extremely compact assembly. Such shearmeans comprises an upper shear blade 39 which extends transversely ofthe strip and is somewhat longer than the strip width. This blade issecured in any suitable manner to an upper shear support 40 which is inturn removably secured to the underside of carriage arm 26 by means oftoe clamps 41. A lower shear blade 42 is secured to a lower shear bladesupport 43 which is fastened to a vertically shiftable platen 44 bymeans of suitable capscrews. In the position of parts shown, upper shearblade 39 is spaced above the normal path of strip travel while lowershear blade 43 is normally spaced below the strip travel path. It willbe understood that when platen 44 is elevated by means later to bedescribed, the lower shear blade will cooperate with the upper shearblade (see also FIGURE 19) to transversely shear strip disposed betweenthe blades.

Since setting up a pair of shear blades for proper shearing action is acritical, time-consuming operation, it is preferable that this be doneat leisure in the machine shop, for example, where facilities areavailable, rather than setting up the blades in situ in the joiningapparatus. When this can be done, considerable down time of the joiningapparatus can be avoided.

In order to permit the shear blades to be set up outside of the joiningapparatus and as seen in FIGURE 11, upper shear blade support 40 has adepending guide pin 45 anchored therein to the rear of the path of striptravel which is slidably received in a guide bushing 46 carried by thelower shear blade support 43. Similarly, and to the front of the path ofstrip travel, a guide pin 47 depends from the upper shear blade support40 and is slidably received in a guide bushing 48 carried by the lowershear blade support 43. The arrangement is such that the guide pinsguide movement of the lower shear blade 42 toward and away from theupper shear blade 39 during vertical movement of the platen 44.

While guide pin 45 is anchored in the upper blade support 40, guide pin47 is slidable in a bushing 49 carried by such support. Guide pin 47 isremovably secured in end-to-end relation to a plunger 50 by means of abolt 51 and this plunger is pivotally connected to a lever 52 which ispivoted within the upper carriage arm 26 at 53. For a purpose to appear,a fluid cylinder 54 is pivotally connected to the lever 52 for elevatingthe pin 47 from its full-line position shown to its phantom-likeposition where in its lower end is spaced above the plane of striptravel.

When the shear means is to be removed from the carriage throat forreplacement or for maintenance purposes, the capescrews holding thelower shear support to the platen 44 will be removed and the screw 51connecting the guide pin 47 to the plunger 50 loosened sufficiently todisengage this pin from the plunger. Toe clamps 41 may next be removedto detach the upper shear support from the upper carriage arm. Theentire shear assembly, including the two shear blades, their respectiveshear supports and the guide-pins may now be removed as a unit from thecarriage. Unitary replacement of the shear means may quickly be effectedin but a few moments by reversing the above steps, it being understoodthat the shear blades in the replacement unit were previously set up forproper shearing action since the guide pins 45, 47 maintain the shearsupports and thus the shear blades in the same alignment away from thejoining apparatus that they assume when mounted in the carriage throatthereof.

Turning now to the means for effecting elevation of platen 44 to effectthe shearing operation previously described, and as best seen in FIGURES7 and 11, platen 44 has a depending web 55 straddled by pairs of links56 which have one end pivoted thereto at 57. The opposite ends of suchlink pairs are pivoted to a bar 58 at 59. Also pivoted to the bar 58 at59, are the upper ends of respective links 60 whose lower ends arerespectively pivoted to the lower carriage arm 27 at 61. From theforegoing, it will be clear that the links 56, 60 form a togglemechanism for multiplying the force exerted by a fluid cylinder 62pivoted to the bar 58 at 63 and pivotally anchored to the lower carriagearm at 64. For preventing horizontal movement of the platen 44, its web55 may be confined between and slidable on members 65 which form a partof the carriage lower arm 27. Although not shown, any suitable means maybe employed to prevent horizontal platen movement in a plane transverseto that in which the members 65 function.

Normally, when a shear mechanism is mounted between cantilever supportedarms, the latter and the structure which ties them together at theirsupported ends must be made quite large and heavy to provide snflicientrigidity to obviate excessive arm deflection as a result of the armseparating forces developed by the shearing operation. In the presentstructure, however, a novel and very effective arrangement is employedto prevent deflection of the cantilever supported carriage arms 26, 27without using a very massive, costly structure.

As best seen in FIGURES 5 and 6, a pair of pins 66 are anchored to thefront wall structure -18 of the base 17 at the level of the lowercarriage arm 27 and a similar pair of pins 67 are anchored to such wallstructure at the level of the upper carriage arm 26. These pins projectrearwardly toward the base wall 19 and are respectively closely butslidably received within lugs 68 carried by the free ends of respectivecarriage arms.

With the carriage disposed in its shearing position seen in FIGURE 6,the pins 66, 67 are seated in the arm lugs 68 and effectively tie thefree ends of the carriage arms 26, 27 together, through the front wallstructure 18 of the base 17, against the heavy separating forcesdeveloped when strip is sheared. However, upon rearward carriagemovement, the arm lugs pull away from the pins and thus the left (orfront) ends of the carriage arms are free to clear the strip disposedtherebetween.

It is an important feature of the present invention that each strip endis tightly clamped before it is sheared, that it is sheared closelyadjacent the place where it is clamped, and that each strip end remainsclamped until the operation welding the strip ends together iscompleted. This is accomplished by strip clamping structure next to bedescribed.

With reference to FIGURE 7, a pair of strip clamping structure areprovided, an exit clamp assembly 69 to the left (in the position ofparts viewed) of the line of shear and an entry clamp assembly 70 to theright of the line of shear. Since these assemblies are very similar,only the exit clamp assembly will be described in detail andcorresponding entry clamp assembly parts will be identified with thesame reference characters but with the suflix a added. Where, however,the clamp assemblies differ in material respects, such differences willlater be specifically pointed out.

Exit clamp assembly 69 comprises a generally rectangular frame 71 formedof side walls 72 at opposite sides of the path of strip travel (see alsoFIGURE joined by an integral, vertically extending wall 73. As hereinshown, frame 71 is spaced some distance longitudinally of the strip fromthe line of sheer. Wall 73 has a horizontally elongated opening 74 atthe strip pass line through which the strip extends and pivotallyattached at one end to each frame side wall 72 by pivot pins 75 are apair of parallel, vertically spaced links 76 whose opposite ends arepivoted at 77 to ribs 78 (FIGURE 10) which are integral with the base17.

Extending transversely of the path of strip travel is an upper clamp arm79 herein shown formed integrally with the frame 71: As illustrated, arm79 projects from the frame toward the line of shear and terminatesclosely thereadjacent in a replaceable wear strip 80. Underlying theupper clamp arm is a lower clamp arm 81 which is pivoted between theframe side walls 72 at 82 and terminates closely adjacent the line ofshear in a replaceable wear strip 83. Lower clamp arm 81 has an upwardlyangled portion 84 on each side of the path of strip travel and eachterminates in a pivot 85 to which is attached the piston rod ofrespective fluid cylinders 86 (hereinafter to be referred to as clampcylinders) whose opposite ends are pivotally connected to an upwardlyprojecting portion 87 of respective frame side walls 72.

From the foregoing, it will be understood that when the clamp cylinders86 are simultaneously actuated to extend their piston rods, lower clamparm 81 will be shifted about its pivot 82 to grip strip disposed betweenthe jaws provided by respective Wear strips 80, 83.

Means are provided for elevating the frame structure 71 (together withthe attached lower clamp arm 81) and in the present embodiment, a link88 is pivotally attached to each frame side wall portion 87 and projectsupwardly through an aperature in the base top wall 20 for pivotalconnection to one end of respective bell crank members 89. Members 89may be secured to a pivotally supported shaft 90 which connects suchmembers for unitary movement.

The means provided for elevating the entry clamp structure 7 0 issubstantially a duplication of that employed with exit clamp structure71; accordingly, such means are also identified with the same referencecharacters but with the suffix a added.

Pivotally connecting the opposite ends of adjoining bell crank members89, 89a are respective links 91 and to the right-hand end of each link91, a pivotally mounted fluid cylinder 91 (each hereinafter to bereferred to as clamp lift cylinder) is pivotally connected. For reasonsto appear later, a link extension fluid cylinder 93 is interposed ineach link 91 intermediate the bell-crank members 89, 89a for the purposeof increasing the length of respective links 91 at an appropriate stageof the operation.

It will now be evident that when the clamp lift cylinders 92 areactuated to extend their piston rods, links 91 will be moved to the leftthus causing bell crank members 89, 89a to rotate about their respectiveshafts 90, 90a. This will exert an upward pull on the links 88, 88a thussimultaneously elevating the exit and entrance clamp assemblies. Uponactuation of the clamp lift cylinders to retract their piston rods, theclamp assemblies will again be lowered, respectively threaded stopmembers 94 functioning to adjustably limit downward clamp membermovement. For reasons later to be discussed, the links 76, 76a ofrespective clamp assemblies constrain the latter to arcuate movementduring elevation and lowering thereof.

One of the principal differences between the exit and entrance clampassemblies is that while the former is pivoted directly to the base 17by its link pairs 76, the latter is pivoted at 77a to repsective slides95 by its link pairs 76a. Slides 95, only one of which can be seen inFIGURE 7, are vertically shiftable by means of a suitable screwthreadedmechanism 96, such shifting of the slides causing a change in thearcuate path of movement of the entry clamp structure 70 for a purposeto appear.

Returning once again to FIGURE 5, entry pinch rolls 13 comprise threevertically spaced rolls; and upper roll 97, a lower roll 98, and anupper intermediate roll 99. Means not shown, are provided "for rotatingthe intermediate roll, the upper and lower rolls merely being idlerrolls. Any suitable means, such as fluid cylinders, may be employed toshift the rolls 97 and 98 toward and away from roll 99 to respectivelygrip and release strip disposed therebetween. Furthermore, although notshown, means are also provided for bodily shifting all three of theserolls vertically to align either the pass between rolls 97, 99 or thepass between rolls 98, 99 with the strip pass line of the joiningapparatus.

Exit pinch rolls 14 are quite simple, such rolls merely comprising anupper roll 100 and lower roll 101 between which the strip passes fromthe joining apparatus to the strip processing line. Means are providedfor selectively moving the rolls 100, .101 toward each other to gripstrip therebetween and at least one of such rolls may be driven.

With reference to FIGURE 1, an important feature of the presentinvention is the previously mentioned strip entry tables 15, 15a whichare preferably identical except for their location. Table 15 issupported on a base 102 for underlying the strip Sa closely adacent theentry pinch rolls 13 while table 15a may be similarly supported forunderlying the strip S.

Table 15, as seen in FIGURE 18, comprises a flat portion 103 margined atone edge of the strip by rectilinear flange portion 104. Table portion103 and its coextensive flange portion .104 extends some distancelongitudinally of the strip for a purpose to appear. Embedded in thesurface of table portion 103 are a plurality of electromag nets 105which, when energized, hold the strip Sa tightly against the table.

Extending transversely of the strip and supported by the base 102 are apair of parallel rods 106 along which the table 15 is slidable. A fluidcylinder 107 is supported by the base 102 and has its piston rod 108connected to the table flange portion 104 for the purpose ofreciprocating the table along the rods 106.

Table 15a is preferably identical to table 15 and may be supported on abase (not shown) similar to 102 or even on an extension of base 102.Table 15a, of course, is also mounted for reciprocation in a directionedgewise of the strip by means of a fluid cylinder identical to 107hereinabove described.

As seen in FIGURE 2, a strip edge sensing device 109 of any suitabletype is disposed at the exit side of the strip joining apparatus and isoperably connected to respective table shifting cylinders 107 where bythe flange portion 104 of each of the tables is continuously maintainedin predetermined relation with the edge of the strip exiting from thejoining device. Normally, each flange portion 104 will be maintained inprecise alignment with such strip edge for reasons to appear.

With the parts positioned as seen in FIGURES 1, 5, 6, 7 and 11, strip Swill be fed from the coil on pay-off reel 12, over the roll 16 under theroll 97 of the entry punch rolls 13, through the joining device 10, theseparated rolls of the exit pinch roll set 14 and to the processing line11. As may be best seen in FIGURE 7, the strip freely travels betweenthe open entry and exit clamp assemblies 70 and 69 respectively andbetween the separated shear blades 39, 42. Note that the entry table ais disposed beneath the path of strip travel so as not to interferetherewith.

A coil of strip So is shown mounted on the pay-01f reel 12a with theleading strip end resting on the entry table 15 and projecting betweenthe separated rolls 98, 99 of the entry pinch roll set 13. In placingthe strip S on the entry table 15, the operator will push the againstthe table flange portion 104 and then energize the table electromagnets105 to retain the strip tightly upon the table. With the edge of stripSa against the table flange 104, such strip edge will be maintained inalignment with the traveling strip Sa as a result of the operation ofsensing device 109 and the table shifting cylinder 107.

When substantially all of the strip S on pay-01f reel 12 has beenunwound, a small amount normally being retained thereon since it isusually undesirable to run it through the processing line, the travel ofstrip S will be terminated and the entry rolls 97, 98 and 99 movedtogether to grip respective strips S, Sa. Magnets in entry table 15 maynow be de-energized since the latter has served its functions ofmaintaining strip Sa aligned with the trailing end of strip S and thefunction of maintaining the strip Sa against undesirable displacementhaving now been taken over by the rolls 98, 99 of entry roll set 13.

Clamp lift cylinders 92 may now have their piston rods extended to raisethe entry and exit clamp assemblies 70, 69 from the positions shown inFIGURES 7 and 12 to the positions shown in FIGURES 8 and 13.Substantially at the same time, clamp cylinder 86 will be actuated toclose the jaws of upper and lower clamp arms 79, 81 of the exit clampassembly on the strip S as illustrated in FIGURES 8 and 13. Note thatthe strip S has been elevated by the exit clamp assembly to shearingposition wherein it abuts the underside of the upper shear blade 39.Exit pinch rolls 100, 101 may, if desired, be closed on the strip S, itbeing understood that the entry clamp assembly remains open, asillustrated, at this time.

Shearing of the strip S transversely will next take place by elevatingthe lower shear blade 42 to cooperating relation with the upper shearblade 39 by means of the fluid cylinder 62. Following shearing of thestrip S, blade 42 will be lowered to the position illustrated and theexit clamp assembly will be further elevated from the position seen inFIGURES 8 and 13 to the position seen in FIGURES 9 and 14 by extendingthe piston rods of link extension cylinders 93. This raises the trailingend of strip S for a purpose next to appear.

The entry pinch rolls of the roll set 13 will now be raised from theposition seen in FIGURE 1 to the position seen in FIGURE 3. Thissubstantially aligns the pass between rolls 98, 99 with the pass line ofthe strip through the joining apparatus. Intermediate roll 99 of theentry roll set 13 will now be rotated in the direction of the arrow towithdraw the scrap end of strip S from between the entry clamp arms 79a,81a and to feed the leading end of strip Sa therebetween and beyond theshear blades 39, 42 as seen in FIGURES 9 and 15. Note that the exitclamp arms are at this time raised out of the path of the entering,leading strip end Sa. Although not shown, suitable guides will beprovided to insure entry of the leading end of strip Sa between theentry clamp arms. Pay-01f reel 12 may now be rotated in a direction towind thereon the scrap end of strip 5 remaining attached thereto.

With the leading end of strip Sa positioned as seen in FIGURES 9 and 15,entry clamp cylinder will now be actuated to close the jaws of upper andlower clamp arms 79a, 81a on the strip Sa as illustrated in FIGURE 16.Note that the strip Sa is thus held in shearing position wherein itabuts the underside of the upper shear blade 39. Shearing of the stripSa transversely will next occur by momentarily elevating the lower shearblade 42 to coopcrating relation with the upper shear blade 39 and thenonce again lowering the lower shear blade. The sheared off portion ofstrip Sa will gravitate down a discharge chute (not shown) and may laterbe removed by the operator.

Upon the return of the lower shear blade 42 to its lowermost positionillustrated, the clamp lift cylinders 92 and the link extensioncylinders 93 will be actuated to retract their piston rods to thuspermit the clamp assemblies to fall to their lowermost positions seen inFIG- URE 17. Since the exit clamp assembly was previously raised higherthan the entry clampassembly, the latter will reach its lowermostposition first and since the clamp assemblies move in an arcuate pathabout their supporting links 76, 76a, the severed strip ends will beslightly overlapped with the trailing strip end S on top of the leadingstrip end Sa.

As herein shown, the strip ends have been overlapped their minimumamount which, in the present embodiment, is approximately fortythousandths of an inch. However, in the event a greater amount ofoverlap is desired, it is 9 only necessary to lower the slides 95(FIGURE 7) by means of the screw-threaded mechanism 96.

With the strip ends overlapped as seen in FIGURE 17, the lower weldwheel 33 will be raised by its cylinder 35 and the front shear pin 47(see FIGURE 11) raised from its full-line position across the plane ofthe strip to its phantom-line position spaced above such plane by meansof the pin lift cylinder 54. The carriage 24 will now be shifted by itsmotor unit 31 to the right as seen in FIG- URE 6. As the juxtaposed weldwheels pass over the overlapped strip ends, a suitable mechanism willturn on the welding current which will pass from one Wheel to the otherthrough the overlapped strip ends and the latter will be fused togetheras a result of the heat of fusion caused their resistance to currentpassage and by the pressure exerted by the weld wheels.

Still referring to FIGURE 6, the weld progresses from left to right andwhen the weld wheels reach the right edge of the overlapped strip ends,the weld current will be turned off, the exit and entry clamp arms 79,81 and 79a, 81a respectively will be opened once again to positions seenin FIGURES 7 and 12, the rolls of entry and exit pinch roll sets 13, 14will be separated, the lower weld Wheel 33 will be lowered, and thestrip once again permitted to travel unimpeded through the joiningapparatus to the processing line. At this time, however, strip Sa willbe fed to the processing line from the reel 12a.

The carriage may now be returned to the full-line position seen inFIGURE 6 and the pin 47 once again lowered to the full-line positionshown in FIGURE 11. The operator may now remove the previously mentionedpiece sheared from the leading end of strip Sa and also remove the scrapend of strip S remaining on pay-01f reel 12. A new coil of strip S maynow be loaded on the reel 12 and its leading end passed over the roll16, over the entry table 15a and between the now open rolls 97, 99 ofthe entry roll set 13 (see FIGURE 4). The strip S will be pushed againstthe upstanding flanges of the entry table 15:: and the table magnetsenergized to maintain the strip firmly on the table. Strip S will now bemaintained in alignment with the strip Sa through operation of the stripsensing device 109 and the entry table shifting cylinder.

Nothing further need be done until such time as the coil of strip Sa isdepleted; however, the operator may, if desired, readily inspect theweld wheels 32, 33 through the opening in front wall 18 and may dressthe periphery of such wheels, if necessary.

When all or substantially all of the strip Sa has been unwound from thecoil on reel 12a and fed to the processing line, longitudinal feeding ofthe strip Sa will be stopped, it will be clamped and sheared by thejoining device, the scrap end of a strip Sa will be withdrawn from thejoining devices and the leading end of strip S will be fed into thejoining device and clamped, sheared and welded to the trailing end ofstrip Sa, all in the manner similar to that previously described; thistime, of course, Sa being the trailing strip and S being the leadingstrip.

In some operations, the welded seam which joins respective strip endsmust be removed at the exit end of the processing line. Accordingly,means are provided for marking the strip ahead of the seam for positiveidentification thereof by, for example, an electric eye device (notshown). As herein disclosed and with reference to FIGURE 7, exit clampframe 71 supports a punch structure 110 which comprises a slide 111which carries a pair of punches 112 which closely fit within aperturesin the upper clamp arm 79. Carried by the lower clamp arm 81 are pair ofhardened sleeves 113 in alignment with respective punches 112 and of asize to closely receive them. Finally, a fluid cylinder 114 is carriedby the frame 71 for reciprocating the slide 111. In the interest ofsimplicity such structure 110 has been omitted from FIG- URES 8 and 9.

Punch structure 110 will be actuated during the time interval that theexit clamp arms 79*, 81 are closed on the 10 strip and at such time,cylinder 114 will momentarily push the punches 112. down through thestrip and into the sleeves to thus pierce two holes in the strip.

When strip is sheared, as shown in exaggerated relation in FIGURE 19,the adjoining knife edges are moved toward each other to progressivelycut into respective sides of the strip until the latter is nearly cutthrough as illustrated. During the final stages of blade movement,however, the remaining neck of material 115 connecting the stripportions on opposite sides of the blades tends to be squeezed off, alongthe plane 116, to thus leave a ragged projecting edge 117 (FIGURE 20).Since such edge is very sharp and is, moreover, work-hardened, it willcause rapid weld wheel wear if the wheel bears against it during thewelding operation.

With reference once again to FIGURE 19, it will be noted that the strippiece to the left of the line of shear will have its burred edge facingdownwardly while the strip piece to the right of the line of sheer willhave its burred edge facing upwardly. Accordingly, since the shearedtrailing strip end is at the left of the line of shear and the shearedleading strip end is at the right thereof, and since the trailing stripend is disposed above the leading strip end during welding asillustrated in FIGURE 20', the burred edges are turned inwardly wherethey cannot cause rapid weld wheel wear as the wheels are drawn alongthe overlapped strip ends during the welding operation.

While the function of exit pinch rolls 14 has not heretofore beenpointed out, it is to be understood that in the present embodiment theywill only be used to shift the strip if, after a weld is made, it shouldbe desirable to shear the welded juncture of the two strips out in theevent the weld is defective or to permit close inspection of the weld.They may also be used to shift the strip when, after the trailing end isonce sheared, it should be necessary to shear such end a second time if,for example, the first shearing operation was not satisfactory.

In view of the foregoing, it will be apparent to those skilled in theart that we have accomplished at least the principal object of ourinvention and it will also be apparent to those skilled in the art thatthe embodiment herein described may be variously changed and modified,without departing from the spirit of the invention, and that theinvention is capable of uses and has advantages not herein specificallydescribed; hence it will be appreciated that the herein disclosedembodiment is illustrative only, and that our invention is not limitedthereto.

We claim 1. Apparatus for joining strip sections in end-to-end relationcomprising clamp means for holding leading and trailing strip ends inadjoining relation, joining means for securing said strip ends togetheralong a transverse line of juncture to form a continuous strip, andstrip marking means for removing a portion from a strip section at aplace spaced a predetermined distance longitudinally of said line ofjuncture of the strip ends.

2. The construction of claim 1 wherein said strip marking meanscomprises a punch which forms an aperture in the strip section.

3. The construction of claim 1 wherein said strip marking meanscomprises a punch mechanism which forms a pair of adjoining apertures inthe strip section.

4. Apparatus for joining longitudinally movable strip sections inend-to-end relation comprising joining means for securing a trailingstrip end to a leading strip end along a line of juncture extendingtransversely of the strip ends,

clamp means for holding the leading and trailing strip ends in adjoiningrelation during juncture thereof, one of said clamp means beingsupported at a place spaced longitudinally of the strip from said lineof juncture and having portions projecting toward said line of junctureand terminating in strip gripping surfaces thereadjacent, and stripmarking means intermediate said clamp means place of support and saidline of strip juncture for removing a portion from a strip section.

5. The construction of claim 4 wherein said strip marking meanscomprises a punch which forms an aperture in the strip section.

6. The construction of claim 4 wherein said strip marking means iscarried by said one clamp means.

7. The construction of claim 6 wherein said strip marking meanscomprises a punch mechanism which forms a pair of adjoining apertures inthe strip section.

8. In apparatus through which stripmaterial normally travelslongitudinally in a predetermined direction and having means for joiningthe trailing end of a first strip to the leading end of a second stripto form a continuous strip length, the improvement comprising:

first vclamp means spaced from said joining means longitudinally of andopposite the normal direction of strip travel and clamping the leadingend of the second strip against longitudinal movement and retaining suchend in a position spaced flatwise of the path of travel of said firststrip while the latter is traveling through said apparatus,

second clamp means closely adjacent said joining means and having firstand second portions disposed on op posite sides thereof relative to thenormal direction of strip travel for respectively clamping said firstand second strips prior to operation of said joining means, and

shifting means for effecting movement of said first clamping means andthe leading end of said second strip clamped thereby in a direction fromside edge to side edge of such second strip end, said shifting meansbeing responsive to the position of a side edge of the trailing end ofsaid first strip to dispose the leading end of said second strip inpredetermined relation with the edge aforesaid of the trailing end ofsaid first strip.

9. The construction of claim 8 wherein said shifting means is responsiveto the position of a side edge portion 12 of the trailing end of saidfirst strip which is spaced longitudinally of said joining means in thenormal direction of strip travel.

10. The construction of claim 8 wherein said shifting means comprisessensing means spaced longitudinally of said joining means in the normaldirection of strip travel for sensing the position of the side edge ofthe trailing end of said first strip.

11. The construction of claim 8 wherein said second clamping means isengageable with a side edge of the leading end of said second strip.

12. The construction of claim 8 wherein said second clamping means has atable-like portion for underlying and supporting the leading end of saidsecond strip, and wherein said table-like portion has shoulder meansengageable with longitudinally spaced portions of a side edge of theleading end of said second strip.

13. The construction of claim 12 wherein said strip is magnetic, andwherein said table-like portion has a magnet for attaching a flat sideof the leading end of said second strip thereto.

References Cited UNITED STATES PATENTS 2,800,567 7/1957 Cooper 219-822,827,809 3/1958 Beam 226-194 3,017,495 1/1962 Woodwaid 219-82 3,021,4162/1962 Mallett et a1 21982 3,102,189 8/1963 Jones et a1. 219 -823,198,413 8/1965 Cooper 219--82 X RICHARD M. WOOD, Primary Examiner.

B. A. STEIN, Assistant Examiner.

US. Cl. X.R. 226-19

